Display devices, such as projectors and flat-panel displays, display image data that is received from video source devices, such as DVD players, cable TV and satellite TV set-top boxes, video cassette players or recorders, and the like. As such, display devices have one or more video inputs that are receptive to connecting cables. The connecting cables connect the video source devices to the display devices in accordance with a predetermined format or form factor, such as s-video, component video, composite video, VGA, HDMI, and DVI.
When a display device is not functioning as expected, such as when a user expects it to be displaying image data from a given video source device and the display device is not displaying the image data, many different potential causes of the problem have to be examined. The connecting cable from the video source device to the display device may be defective, the video source device may be defective, or the display device itself may be defective, for instance. Each potential cause of the problem should be examined and ruled out, until the actual cause of the problem is discovered. However, ruling out potential causes of the problem can be difficult for the average user to accomplish.